Large Strain Consolidation in Unsaturated Porous Media

Gareth presented a consolidation model that allows for the effects of desiccation which is prevalent in slurried mineral waste deposits in areas of high evaporation. The coupled model is based on conventional large strain consolidation of saturated porous media extended to include the effects of partial saturation using the Richards equation. The model can accommodate …more

Evaluation of the Stability of an Arch Dam Founded on Fractured Rock

Antonio outlined a case study involving three dimensional finite element analysis of a 150m high arch dam founded on fractured Cretaceous limestone. Key constraints were limited abutment resistance and unfavourable defect orientation. Details of data acquisition including in situ rock mass shear testing were presented. The finite element analysis modelled discontinuities using individual joint elements …more

Discrete Element Modelling in Soil Mechanics

An alternative to the Finite Element Method, the Discrete Element Method is particularly suitable for modelling granular materials and for studying the relationship between `micro’ and `macro’ behaviour. Discrete Elements allow contacts between elements to be created or broken and can therefore be used to gain insight into the processes of nucleation and growth of …more

Stress-Deformation Behaviour of an Embankment on Boston Blue Clay

An 11m high embankment was thoroughly instrumented with piezometers, settlement rods and inclinometers to measure the behaviour of the underlying 40m thick deposit of Boston Blue Clay during staged loading and four years of subsequent consolidation. estimates of the engineering properties of the clay were made based on in-situ testing and laboratory test programs. Finite …more

Failures, Factors of Safety and Soil Strength

In routine geotechnical design of foundations, slopes and retaining walls a factor of safety is applied to ultimate collapse loads. But very different factors of safety are used for different structures. Also soil has several different strengths; peak, constant volume (or critical state) and residual. Moreover, it is not always clear what constitutes failure of …more

EUROCODE 7 Part 3 : Field Testing – Methods & Interpretation

Professor Drozd is a long serving member on this Eurocode committee. Professor Karel Drozd presented the approach of Eurocode 7 to different methods of field testing and analysis of the results. Special reference was made to the limit states nature of this code. The presentation was illustrated by examples from his personal experiences through using …more

Evolution of strain localisation in granular materials

It is experimentally evident that large monotonic shearing of a granular material causes a concentra-tion of the shear deformation into narrow zones along walls or inside of the granular body. Location, orientation and the evolution of strain localisation is determined by the mechanical properties of the granular material and the boundary conditions of the described …more

Geotechnical Analysis

The design of any geotechnical structure of significance requires the quantification of safety and in some cases movements. To achieve this the designer must perform calculations using some form of analysis. At present there are several forms of analysis available, all of which involve simplifications and approximations. This lecture will begin by briefly comparing these …more

Tomago Mineral Sands Mining Project

This project was recently acknowledged by the Association of Consulting Engineers Australia (ACEA) in their Engineering Excellence Awards for 1999. For the past 20 years Douglas Partners have been advisors the water authority (initially HWC, and subsequently DLWC) in monitoring the effects of mineral sands mining on the Tomago Sandbeds aquifer. The Sandbeds are also …more

Shear Strength and Stiffness of Silty Sand

The stiffness and shear strength of clean sands have been studied extensively. However, natural sands generally contain significant amounts of silt and/or clay. The mechanical response of such soils is different from that of clean sands. This lecture addresses the effects of non-plastic fines on the small-strain stiffness and shear strength of sands. A series …more

The mysteries of blast induced ground vibrations

There are often anomalies between the expected level and the actual monitored level of blast induced ground vibrations. The main theme of this talk highlights the effect of the degree of confinement of an explosive charge on the magnitude of the shock wave transmitted through the ground. An analysis of the energy distribution of an …more

Assessment of regional landslide hazard

The process of assessment of the risk of landsliding involves consideration of the likelihood of a landslide event occurring and also the consequence of that event. A primary requirement is an estimation of the level of hazard that exists i.e. whether a landslide could occur, and if so, its probable frequency. This estimation is commonly …more

Geotechnical Anchoring Systems and GEWI Piles

The lecturer will first present a summary of the geotechnical anchoring systems offered by DYWIDAG-Systems International using bar and strand. The focus will then be on GEWI-Piles: a minipile system that uses steel Threadbars grouted in small drilled holes. The grout body encasing the Threadbar provides corrosion protection, enables load transfer into the rock or …more

Geotechnical Aspects of Kooragang Coal Terminal Stage 3 Expansion

The Stage 3 Expansion of the Kooragang Coal Terminal is a $345 million project, which will boost the coal exporting capacity of the Port of Newcastle from 77 million to 89 million tonnes per year. Port Waratah Coal Services appointed Bechtel Australia in July 1999 to design and construct the expansion. The key construction elements …more